Low back pain is a common health problem in industrialized societies. Studies suggest that low back pain originates from a number of spinal structures; however, the most common sources of pain are musculoligamentous injuries and age-related intervertebral disc degeneration. The intervertebral disc structure consists of the nucleus pulposus, annulus fibrosus and cartilaginous end-planes, the composition of which changes significantly with age, creating difficulty in differentiating structural changes related to age versus those associated with degeneration and back pain.
Disc structure can be accurately visualized with both computed tomography (CT) and magnetic resonance imaging (MRI); however, the correlation between disc morphology and back pain origin is poor. Current imaging methods are fundamentally limited due to their morphological assessment of functional changes that occur months to years earlier as well as lack of contrast agents specific for the disc tissues. Low back pain associated with disc degeneration is thought to be due to increased innervation of the annulus fibrosus. When a tear in the annulus fibrosus exists, the tear can be visualized using regional contrast enhancement with CT or MRI
Non-surgical treatments for low back pain are often unsuccessful, and non-responding patients are typically treated with surgical intervention. There are two main surgical techniques used to treat low back pain: lumbar fusion and more recently, total disc replacement. Both techniques rely on image guidance and clear visualization of the nucleus pulposus and annulus fibrosus although presently, specific intraoperative imaging of these structures is not performed.
Therefore a contrast agent specific for the intervertebral disc could assist in the detection, diagnosis, and surgical treatment of low back pain.